Preparing for Winter Concrete

Decreasing fuel use in heating water reduces a product's carbon footprint.

Technicians bolt the heat exchanger to the direct-fired heater's exhaust stack on new or existing tanks for existing Infern-O-Therm heaters or competitor units. Intake water temperature can be raised by as much as 32° F.

Doing more with less is an operational creed by which all producers make their daily decisions. So it's not surprising that these frugal managers often fail to realize that many good operating decisions also provide tangible signs of their company's commitment to sustainability.

Perhaps the best definition of sustainability was penned by the World Commission on Environment and Development: “Forms of progress that meet the needs of the present without compromising the ability of future generations to meet their needs.” Saving fuel during manufacturing is one example of how good business practices are environmentally friendly.

Providing heat for winter concrete production at an economical price meets this definition of sustainability. So as the winter production season approaches and plant managers begin to check their water heating systems, going lean is also going green.

Given tight capital budgets, projects that feature cost savings and environmental improvement just might win corporate approval. With such parameters in mind, producers may want to take a look at a new product introduced last year by Infern-O-Therm Corp., a Keyport, N.J., manufacturer which supplies water heating and cooling equipment to the construction industry.

In response to customer concerns for controlling water heating fuel costs, Infern-O-Therm engineers developed their Pre-Heater Stack Economizer. By lowering the need for BTUs, producers using the device batch a yard of concrete with a smaller carbon footprint.

And since architects and building owners who believe in sustainable construction are looking for examples of how their suppliers have reduced the amount of embedded energy in the manufacturing process, producers who add this feature to their systems have a green talking point.

Redirecting heat

The water heating system traps the heat from a boiler's flu exhaust gas stack and redirects it to preheat supply water entering a direct-fired heating unit. Depending on flow rate and volume, the heat exchanger can elevate the intake water temperature by as much as 30° F.

The system's heart is the heat exchanger bolted to the direct-fired heater's exhaust stack. This system can be installed on new tanks during fabrication or as a retrofit kit for existing Infern-O-Therm and competitor units.

By warming the feed water, the direct fire heater requires less energy to achieve the desired output temperature. How much the system reduces heating fuel demand varies. There are several factors that influence energy consumption when heating fresh concrete. Most importantly, the BTU demand of the heating system will vary, depending on the burner size rating and the length of the fire-tube installed in the tank.

Most producers would benefit. In a recent test using an HW-15-400 Infern-O-Therm, engineers documented a significant embedded energy reduction. The test unit had a 465° F gross stack temperature. The heat transfer system used this stack heat to raise the incoming water temp 32° F above incoming water at a flow rate of 47 GPM. This provides a savings of about 700,000 BTU, or six gallons per hour of fuel oil. Along with greener concrete, the producer may save about $20 per hour in fuel costs.

There's another environmental advantage, albeit one that can be difficult to measure. As heat was drawn into the exchanger, the stack emission temperature level was reduced to 180° F. To environmentally focused clients, showing significant reductions in plant emissions is a good marketing tool.